Heartbreaking text message exchanges between students trapped in the sinking ferry off the coast of South Korea and their anxious parents are offering a glimpse into the desperate situation in the crippled vessel.

"Dad, don't worry. I've got a life vest on and we're huddled together," one 18-year-old student, identified only by her last name, Shin, texted her father, according to MBC News, a Korean news station.

The father replied: "I know the rescue is underway but make your way out if you can."

"Dad, I can't walk out," she replied. "The corridor is full of kids, and it's too tilted."

In another exchange, a male student texted his mother, who was unaware at the time that the ferry was in distress.

"Mom, I might not be able to tell you in person. I love you," the student texted, according to MBC.

"Me too, son. I love you," the mother texted back, followed with three heart symbols.

Fortunately, that student was among the 179 people who have been rescued, MBC reported.

Survivors told harrowing tales of confusion and desperation as people slid along the floor of the sharply listing ship, colliding with one another, or found themselves trapped in cabins by a wall of water.

Rescued passengers said that immediately after they heard a booming noise, the ship began listing and they heard an announcement over the ship's PA system telling the passengers to stay in place.

"The baggage was falling out, and we were saying 'What's going on?' But the announcement told us to stay where we were, so we did," one rescued student told MBC.

"The ship began tilting all of a sudden, and then people started skidding down from above," rescued passenger Young-Ja Shin told SBS News. "There was a railing, so I held onto it, but I then got hit by one of the falling people and we got pushed down to the bottom."

"It took about 10 seconds to tilt over, and then I began sliding from end to end," rescued passenger Eun-Bok Jang, 50, told SBS News. "I got hit on my side and then I couldn't breathe."

The vessel tipped over completely on its side, and there was mass confusion inside the ferry as refrigerators and other things fell over, Jang said.

When the water started rushing in, many passengers put on life vests and escaped outside. But by the time that announcements told passengers to make their way out, the ship had already submerged significantly, so there were few exits that could be used for escape, rescued passengers said.

Many passengers were gathered in the entertainment center, restaurants and shops on the third floor of the 5-deck ship, but when the ferry capsized, that third floor was fully submerged, authorities told the Yonhap news agency. There was most likely a power outage immediately after the ship capsized, so confused and frantic passengers probably had a hard time finding their way out in the dark and narrow passage ways.

"When we were making our way out, the wall was almost all water, and it was completely submerged up to the third floor," survivor In-Hwan Kang, 58, told MBC.

So-Hyun Kim, a teacher accompanying the more than 300 students from Danwon High School in Ansan, said she initially stayed in her cabin because of the announcements, but had to attempt an escape when water came rushing in.

"I couldn't go anywhere. I didn't have the strength to climb further up," she told SBS News. "There was an open emergency exit, so another teacher and I decided to just fall and swim our way toward it. I fell and hit a railing, and that's when I was rescued."

Of the 475 passengers on board the ferry, 179 were rescued. Another 287 were listed as missing and 9 died.

Rescuers were seen boarding the vessel, which had tipped to its side, and combing through the top of the ship for survivors. One man boarded the boat and quickly found what appeared to be a crew member still on it.

Bodies could be seen scattered through the water in another video shot from a helicopter. A yellow raft was tossed out of the chopper and survivors in the water swam toward it before they were pulled to safety.

Others were winched in slings to the safety of hovering helicopters.

As darkness fell, the ferry took on more water and only the rudder of the vessel remained visible before the ship sank about 100 feet below the water. Rescuers stopped searching for those still reported missing at about 7 p.m. due to strong currents and poor visibility, but they resumed their mission around 12:30 a.m. local time, taking advantage of a lull in the strong currents.

One rescued passenger said he believed that many people had been trapped inside the ferry when it sank.

The ferry, identified as the Sewol, was sailing to the southern island of Jeju when it sent a distress call as it began leaning to one side. The passengers include more than 300 students from Danwon High School in Ansan, near Seoul, who were on a school trip.

Yonhap/AP Photo

Rescue crews respond after a ferry sank off the coast of South Korea, April 16, 2014.

Yonhap/AP Photo

The Republic of Korea Coast Guard/Getty Images

The rescue work by members of the Republic of Korea Coast Guard continues around the site of ferry sinking accident off the coast of Jindo Island, April 16, 2014 in Jindo-gun, South Korea.